error while converting xml to json in datapower

Question

when i try to hit xml from soapui i was getting error in response

<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
   <env:Body>
      <env:Fault>
         <faultcode>env:Client</faultcode>
         <faultstring>Rejected (from client)</faultstring>
      </env:Fault>
   </env:Body>
</env:Envelope>

rule is "server to client"

xslt code is:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="2.0" 
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:json="http://json.org/">
    <xsl:import href="xml-to-json.xsl"/>
    <xsl:template match="/">
        <xsl:value-of select="json:generate(.)"/>
    </xsl:template>
</xsl:stylesheet>

but error is seen in logs error_log